Objective       To determine the expression of metastasis-associated in colon cancer-1 (MACC1) in human esophageal squamous cell carcinoma (ESCC)

and investigate its correlation with clinical features for its role in the invasion and metastasis of the tumor.       Methods       The expression of MACC1 in 51 ESCC specimens and para-carcinoma was measured by immunohistochemical staining. The correlation of the MACC1 expression with the clinicopathological features was analyzed in the invasion and metastasis of ESCC. The plasmid harboring MACC1-shRNA was transfected into ESCC cell line ECA109. The stable cells were screened out by G418 and identified by real-time PCR and Western blotting. Then the proliferation

migration and invasion of the positive ECA109 cells were studied by MTT assay and Transwell chamber test.       Results       The positive rate of MACC1 was 94.1% in the obtained ESCC tissues

and was only 37.3% in the corresponding para-cancer tissues (P0.05). MACC1 was strongly expressed in the epithelial cells of ESCC (90.0%)

significantly higher than it in the epithelial cells of atypical hyperplasia esophagus (15.0%

P0.05). No MACC1 expression was found in the epithelial cells of esophagus without obvious hyperplasia. There was no statistically significance in the gender

age

tumor size

location

differentiation and depth of invasion among the ESCC with different MACC1 levels (P0.05). In the in vitro study

MACC1-shRNA transfection resulted in significantly reduced proliferation

migration and invasion in the ECA109 cells.       Conclusion       MACC1 is closely involved in the invasion and metastasis of ESCC. It is abnormally expressed in the esophagus epithelium with atypical hyperplasia and in the ESCC. In the process of atypical hyperplasia to carcinoma

the protein expression of MACC1 is elevated

suggesting its intimate role in the incidence and development of ESCC.